Characterization of Nb SRF cavity materials by white light interferometry and replica techniques

► SRF accelerator cavity interior surface topography provides a key link between processing (fabrication) and performance. ► Topography data analysis by extensions of power spectral distribution (PSD) methods yields important new insights. ► Application of replica methods substantially overcomes the problem of access to the cavity interior surface. ► WLI offers an enormous increase in the rate at which topography data can be acquired, greatly expanding its usefulness.